Shock absoebeb



:JM/manto@ Feb 3, 1931. w. .1. SMITH SHOCK ABSORBER Filed Sept. 12,19249 .l .llllll l I.

Patented Feb.3,1931 y y* y 1,790,773 Y o UNITED sir-Arasv PATENT,V'oFfFicEj WILLIAM J. SMITH, or PHILADELPHIA, PENNSYLVANIA,Assisfivora,A To CHARLES o. IIADLY, or` PHILADELPHIA, PENNSYLVANIA sHooKABsoIeBER Application mea september 12, 1929. Vserieu No. 392,133.v

This invention relates to shock absorbers the inclination of the meetingfaces `of theV intended primarily for use on motor vehicles, screwthreads is too small to insure their and which are available withslightmoditicamoving over each other under the impact. tion for other similarpurposes. Consequently, no action of the parts of the The principalobject of the invention is to shock absorber Vtending to check theSudden 50 provide a shock absorber in which screw mevement or the body,or to absorb shock, threaded interengaging members shall be so takesplace. f e combined as to govern and gradually check, In the shockabsorber which I have dee by reason of the friction between contactingvised provision is made for receiving initially parts, the movements ofa spring-supported the force or". a compressingaor" expanding 55 vehiclebody in a manner to prevent sudden movement 01"" the supporting springso-' a vemovements, or shocks to the body when the hicle uponcomparatively high pitched convehicle of which it forms a part movesover tacting Screwk threads of relatively movable.,` a rough road, overobstructions, depressions, parts of the device, thus insuring operativeetc., and the supporting springs are suddenly movement of the parts,whether'the force ex- 60 compressed or expanded. Another object erted upon them be great or small. f It a small` is to provide a shock absorberof the general force 1s exerted, the fri'ctional contact becharactermentioned in which the parts will tween the parts of the shock absorberhaving be certain of functioning at the inception'ot the highly vpitchedthreads Vwill Serve to:

any movement of a vehicle body induced by check the movement of thevehicle body, and 65 the actions of theV supporting springs as the t oabsorb any attendant shock. Should the vehicle passes over a rough road,obstruction orc'e be 'ot any considerablev amount, too. or depression,and which will gradually great to be checked by the retardingfricehecl;Y such movement and also the counter. tional Contact of thelhigh pitched threads,

movement, as under the action of the springs` similarly contactingcomparativelylow 7 the body is returned to its normal position, pitchedthreads on moving parts ofthe de-' and prevent 511001; 01- jar t0 thebody, vice are automatically brought -intok opera- In the use otinterengaging screw threaded tlOIl, @11d 21S 21 001156611161106 theSpring moveparts, as the active elements, in the construc'- ment 1Sgradually Checked and Shock- 01 im 3C tion of shock absorbers, severalobjectionable to the body of the vehicle prevented. f 75 conditions areencountered, and unless these The gGHGIC daSrlVOlVGd in my device 1 aremodified or overcome the devices in which may b@ @Tried 01115 by the USG0f vftTOllSk they are incorporated are impracticable and Constructions,and a simple form is illus-` fail to perform their designed functions.trated 1n the accompanying drawing.

For instance, it the pitch of the engaging The drawing is a centralvertical sectional 80 screw threads of the coacting parts is too view ofone form of the shoclr absorber, the high, the independent movements 'ofvthe relative normalpositions of the parts lbeing,

parts is too rapid, when conditions arise to shown by dotted lines. f nI contract or expand the vehicle-supporting In this drawing lrepresents-the body ofv 40 springs, and consequently there is little orno the device, which is herein'shown -ascylin-` 855 governing ot theobjectionable movement of drical and provided with a screw coverQ hav?-V the body of the vehicle carried on the springs. ing in its center 'anopening 8 and-provided On the other hand, if the pitch of the threadswith ya stutling boX l surrounding the" open"- of the parts is too lowand a sudden pressure,` ing. The lower closed end y5 ofthe cylinder f inthe nature of a blow, is imparted 4to them, has lextending from` it aprojection or anni. 90

rio

to form means for securing it in position :tor use. Y

The entire inner face Vof the body l is provided with screw threads 7,the pitch of which is determined by the use for which the shock absorberof which it forms a part. For general use, such as upon ordinary inotorcars, the pitch may advantageously be 207, more or less.

Located in the body l and screw threaded both eXteriorly and interiorlyis. a ring or sleeve 8. rlhe screw threads on theeXter/ior of` thiscollar are `out a pitch to yengage and coact with those on theY innerface of the body l, while those on the interior'are of higher pitch.Arranged in the collar 8 fand corresponding in diameter to the interiorof the collar is acylinder 9 provided onitsv outer face with screwthreads which correspond with those on the inner Vface 'of vthe rin-g orcollar 8, and which engage the lat-ter. EXtendingthrough the cylinder 9,and `projecting at itsrupper end through the screw Y cover 2 is a steml0. The st-em l0 is attached to 1the cylinder in ainanner to allowrot-ation Vof the cylinder independently of the stem,

and 4to prevent independent longitudinal movements ofthe parts. Securedto the upper end oli'l the cylinder 9 is a dislr'll of a diameter"greater than that of the cylinder theouteredge of whi'ch'overlaps thering ori-sleeve 8,'an'dk secured to the lower end of the 4cylinfderlis acorresponding disk l2. Y

,The 'stem l0 is provided at its upperexposed end with an enlargedfportion 1S havin'g an opening therethroughfto facilitate its attachmenttoiav part oi the vehicle to which itis to be. applied. y Y

AIn the use of the device its ends Imay be attached, Vfor instance, oneto the upper por-l tio'n o'f'anY elliptical spring of a vehicle and theother Vto the lower lpart thereof-g one Vend mayr'beattachedfto an axleof a vehicle Vand theotherto the spring-heldbody of the vvehicle, or'itmay be arranged in any other .position where its function to' governthe movements ojf they body of the vehicle caused' by compression orAexpansion of the supporting springs may be exercised. l f

'From' the "foregoing the operation of :the sh'oclabsorber will bereadily understood. Assuming 'that the lower end ofthe device `isattached Lto ah iaxleof avehicle vand that Vth'eupper end is ,attachedto the body thereof', and that/the disks yll'and l2A are in ytheirnormalzpositioiis, as Vshown by dotted lines` in the drawing, eachremovedV a shortfdistanceffrom oneend of the cylinder 9, should `theYwheels ofthe vehicle come into vcontact with elevation in the road thebody l of Y the device "and the collar ,8 would be Vmoved upwardly.fThis upward movement would causefa rotation Ofgthe cylinder 9 'in thecollar 8 by reason of ,the interengagingscrew vthreads of thep'arts,l'irrespective of the' the upward movement of the case l andoivthe collar.

It excessive force isimposed on the body l,

the upward movements of the body l and the collar 8 are continued untilthe upperv face of the collar isV brought to contact withthe upper diskll.V `Vwhich 'is attached to the cylinder 9, andthe rotation of thecylinder independently ofAY the collar 8 is checked. Nhen'the parts areAin 'this postion, 'the continued up- Vward'nnoven'ieirt "of-the body lwill cause. the

rotation of the collar 8 within the body. As

"the interengaging teeth of the body and those 1ottlzie,exterior otthecollar are of a pitch Y lower than `those oi Athe 'interior of thecollar and lthe 'cylinder 9, the friction imposed on thesefp'artsisgreatcr, andconsequently the rotation of the collar is graduallychecked and iinally terminated. @n Athe rebound or er?- pansion lcithespring, the jlowerdisll2 being removed from the lower enjd ofthecylinder 9, onl fv moderate resistance is ogered to thorotationocylindecr as thevbfodyl and theco'llar S return to normal positions.y,'Asaghe moya;

ments of these parts approach their terminations, the dise contactingwith tl'iedcollarr 8 causes the collar vand cylinder torotate, and,

by reason of the greater friction thus brought into play., tne downwardmovements Voit the body and collar arey checked and*Y finally K stopped,as inl their upward `inovenieirts.

inasmuch as the beginning of amoveinent,

either up or down, of thefbody l and the col` lar or ringlSlresults in arotationoi the cylinder 9 it will be ,clear that because of Jthefrictionalv` Contact A:of the :parts-'more or less rotation ofthe collaro'r ring; is caused, Therefore, as the inertia'of'the collar or ringthus overcome, whenjone O hedislis of thaietating cylinder contacts withthe ring or collar, the rotationofA the cpllarfor ring-is easilyaccomplished, though the. pitch of thethreads on the outer face ofvtheling jor-collar and those on theinnerface of the body l' are otlowpitch.; By reason oi the pitch of the screw threads on the interiorofthe collarV 8 and AontheY exterior cylinder, when a vehicle losreceives'animpulse tendingto compress or eX- Y panditssupportingsprings, actionto reduce or avoid Vshockto a vehicle bodysupportedby the springs begins instantaiieously,,andr this A action isgradually Acontinued by reason of the frictional oontactgof Vthe threadsot the parts ofthe shock absorber untilthe ,shocksl or jar causedbythe,impulse are absorbed, andthe movements of the parts cease.V Thus,nottinic' will the force ofvyany suddenup or down move'- nie/ nt .of thewheels o :tA a vehicle Abe communicated the form of shocks orfjars to abody carri-ed onV the spi'inds Ethey vehicle.

The pitch of the screw threads of the parts fab of the deivce may bevaried to any extent, according to the use intended. Generally, for useon' light vehicles the pitch would be higher than those for use onheavier ones.

I claim: Y

l. A shock absorber comprising an interiorly screw threaded body member,a cylindrical member having external screw threads of a higher pitchthan those on the body member, and an intermediate member receiving thecylindrical member and having on its outer face screw threadscorresponding to those on the interior of the body member, and having onits inner face screw threads corresponding to those on the cylindermember.

2. A shock absorber comprising an interiorly screw threaded body member,a cylindrical member having external screw threads of a higher pitchthan those on the body member, an intermediate member having on itsouter face screw threads corresponding to those on the body member andhaving on its inner face screw threads corresponding to those on thecylinder member,

and means for causing the cylindrical mem-L ber and the intermediatemember to rotate in unison.

3. A shock absorber ycomprising an interiorly screw threaded bodymember, a cylindrical member having external screw threads of a higherpitch thanthose on the body member and provided at its ends with disksof greater diameters than that of the cylindrical member, and anintermediate member receiving the cylindrical member and having exteriorscrew threads corresponding to those on the body member, and interiorscrew threads corresponding to those on the cylindrical member.

4:. A shock absorber comprising an interiorly screw threaded body, aring or collar located in the body and provided with exterior screwthreads engaging those on the body, and with interior screw threads of ahigher pitch than those on the body member, and a cylinder located inthe ring and having on its face screw threads corresponding to theinterior screw threadsof the ring.

5. A shock absorber comprising an interiorly screw threaded body member,a ring or collar having exterior screw threads engaging'those on thebody member and interior screw threads of a high pitch, a cylinderhaving exterior screw threads corresponding to the interior screwthreads of the collar or ring, the ends of the cylinder being providedwith disks extending beyond its periphery and adapted to contact withthe collar or ring. l l

6. A shock absorber comprising. an interiorly `screw threaded bodymember having means or securing it in place for use, a cylindricalmember. having external screw threads of a higher pitch than those onthe body member, an intermediate member receiving the cylindrical memberand having on its outer face screw threads corresponding ioo

